El concepto de Responsabilidad Social Empresarial

LITERATURE REVIEW

In Chapter I, I discussed the federal and state governmental policies pertaining to education and more specifically, policies related to teaching physics to English language learners (ELLs). Furthermore, I reported increases in the number of ELLs enrolling in physics classes, thus emphasizing that physics teachers are experiencing new challenges related to teaching physics as they create science learning environments effectively serving classrooms of students speaking several languages other than English as their first language. ELLs in high school possess varying levels of English skills, often dependent on the number of years they have attended American schools, where English is the required language of instruction. Subsequently, most ELLs new to living in the U.S. struggle with understanding the subject matter in their classes, which become even more challenging when they must grasp understandings related to abstract science concepts (Lee, 2004; Lee et al., 2006; Lee et al., 2005; Lee & Fradd, 1998), many of which are contrary to the practical knowledge students have accumulated through experience that relates to how the world works.

As a physics teacher in a school district currently serving a diverse population of ELLs from many different countries, I have been concerned for a number of years about ways to help ELLs grasp abstract physics concepts. Above all other topics, Newton's Third Law remains to be one of the most difficult physics concepts for me to teach. Noted in the literature as a difficult concept for English-speaking learners, my

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experiences indicate that the concept is difficult for all learners, but especially difficult for ELLs.

In this chapter, I address two issues. The first issue relates to teaching Newton’s Third Law in high school physics classes, specifically: (a) the importance of Newton’s Third Law to developing an understanding of physics concepts, and (b) the challenges to high school physics teachers in relation to teaching ELLs. The second issue relates to doing research about successful strategies in teaching about Newton's Third Law to ELLs, including (a) specifying the design elements for a research design involving ELLs' learning of Newton's Third Law, and (b) developing research methods to evaluate ELLs’ conceptual understanding, mental models, and language associated with Newton’s Third Law.

Conceptual Framework

The conceptual framework navigating the literature review for this chapter appearing as Figure 2.1 indicates my placement of these issues within a logical

framework for reviewing the literature related to teaching and research issues involving ELLs' learning of Newton's Third Law. Subheadings in this chapter correlate with concepts appearing in the conceptual framework.

32 Figure 2.1. Outline of the literature review.

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Importance of Newton’s Third Law

A conceptual understanding of physics requires an understanding of Newton’s Third Law, which provides basic knowledge of the constructs for how the world works. For example, learners confuse “force” with how fast an object is moving or if the object is increasing or decreasing speed (Hestenes, Wells, & Swackhamer, 1992; Maloney, 1984; Smith & Wittman, 2007). Learners face challenges with application of the law to real world situations, primarily due to the fact that learners bring to the topic an array of misconceptions. These misconceptions are in opposition with the principles of

Newton’s Third Law. In addition to the instructional challenges needed to overcome these misconceptions, teachers of physics learners who are ELLs encounter a unique set of additional challenges in teaching Newton’s Third Law to these learners.

The two instructional interventions chosen for this investigation allow for comparison in ELLs' learning outcomes in computer-assisted and hands-on instruction. The hands-on instruction intervention engages learners in traditional laboratory-based instruction with set-ups of equipment, measuring of variables, and examination of

results. The computer-assisted intervention employs technology in the form of computer simulations designed for learners to develop a better understanding of Newton’s Third Law and to alter existing misconceptions. The computer simulations chosen for the intervention have instructional scaffolding assisting learners in developing a conceptual understanding of forces as the learners manipulate different variables utilizing the inquiry approach. As the variables are being manipulated, the learner is able to observe resulting changes. While research does exist on teaching the concept of Newton’s Third

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Law to physics learners, especially to college students, research involving teaching Newton’s Third Law to high school learners who have limited English skills is

nonexistent, nor do any studies compare two different modes of learning about Newton's Third Law.

In the eyes of Albert Einstein, Isaac Newton’s understanding of the how the world works embodied the greatest of all minds (Krull, 2006), and Newton’s work has affected generations of physicists and their concepts of physics. As an example, before rockets went into space many physicists thought that resistive mass was required for acceleration of motion. Space has little or no mass. Consequently, many physicists thought rockets once in space could not alter movements. The assumption that external mass is required for motion proved false since the propulsion force is acting on the internal spacecraft and therefore produces motion. But, as modern space travel is now possible, the assumption that space is a complete vacuum is also false.

Newton’s Third Law states, “Force of one object on a second is the same size (magnitude) as that on the first by the second, but in the opposite direction” (Smith & Wittman, 2007, p. 1). Newton’s Third Law explains interaction of surrounding forces (Hewitt, 1997). Without a full understanding of Newton’s Third Law, learners are unable to grasp a basic understanding of physics. A learner then easily develops misconceptions and faulty mental models.

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Texas mandates the Texas Essential Knowledge and Skills standards for physics. Section 4C of TEKS requires that students know the laws governing motion, and expects students to demonstrate the effects of forces on the motion of objects. For example, in high school physics students should develop a conceptual framework of forces as exhibited in the following TEKS statement:

(4) Science concepts. The student knows and applies the laws governing motion in a variety of situations. The student is expected to: (D) calculate the effect of forces on objects, including the law of inertia, the relationship between force and acceleration, and the nature of force pairs between objects;

(http://ritter.tea.state.tx.us/rules/tac/chapter112/ch112c.html#112.39 retrieved 3-19-2011).

In addition to state mandates, the National Science Education Standards as set forth by the NRC (1996) state, “Whenever one object exerts a force on another object, a force equal in magnitude and opposite in direction is exerted on the first object” (p. 180). The Benchmarks for Science Literacy (1993) under the subtitle Motions and Forces

states, “Whenever one object exerts force on another, a force equal in magnitude and opposite in direction is exerted on the first object” (p. 179).

Challenges to High School Physics Teachers

Challenges of learners’ misconceptions. Christian and Belloni (2004) investigated

the efficacy of changing learners’ misconceptions and beliefs through interactions with computer simulations. These researchers substantiated that the use of visual

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models (Christian & Belloni, 2004). Others have noted the importance of learners’ being actively involved in constructing conceptual knowledge (e.g., Leonard, Dufresne, & Mestre, 1996). Learners need to be able to manipulate variables while interacting with computer simulations in order to develop conceptual understanding. A learner’s ability to actively work and assimilate material in order to make sense of it is consistent with research findings (Leonard et al., 1996). A computer simulations enhance a learner’s understanding when it contains animation, engages learners, controls access to variables, and limits time and number of variables (de Jong, Martin, Zamarro,

Esquembre, Swaak, & van Joolingne, 1999). Computer simulations with these qualities result in increased intuitive knowledge of the learner.

The NRC (2000a) defines a misconception as an incorrect thought that has part or all of the ideas associated with a concept. Other words associated with the concept of misconceptions have been used (see Table 2.1). These include alternate or common naïve conceptions and common-sense beliefs. Obstacles to learning physics are often entangled in personal common-sense misconceptions that learners hold about the way the world works. Derived from the learners’ observations of the world around them, these misconceptions become the learners’ explanations (Dykstra, Boyle, & Monarch, 1992; Hudson, 1984; Maloney, O’Kuma, Hieggelke, & Van Heuvelen, 2001), developed over time by interacting with the environment (Maloney, 1984). Since misconceptions are often deeply rooted and difficult to change, learnerswho tightly adhere to them are not able to fully benefit from instruction (Dykstra et al., 1992).

37 Table 2.1

Words and Phrases Associated with the Identification of Incorrect Conceptual Understanding

Words and phrases References

Alternate conceptions Maloney, 1984; Redish, 2003b

Aristotelian Halloun & Hestenes, 1985a

Common naïve conception Redish, 2003b

Common sense beliefs Halloun & Hestenes, 1985a

Facets Minstrell, 2008

Initial conceptions Maloney, 1984

Mental models – can contain misconceptions, part or whole

Bao, Hogg, & Zollman, 2002; Redish, 2003b

Misconceptions Minstrell, 1982; Hammer, 1996; Redish, 2003b

Preconceptions National Research Council, 2000b; Redish,

2003b

Student views Thornton, 1997

An example of a misconception in physics when learning Newton’s Third Law can be found in a student’s attempts to describe an interaction between a larger object and a smaller object. Learners incorrectly think that the larger object exerts a greater force on the smaller object. In reality, the amount of force exerted by the larger object is the same as the force exerted by the smaller object. The direction of the forces is

opposite. As Newton’s law states, the forces are equal in magnitude but in the opposite direction. Another example of a common misconception is the thought that a moving object exerts a larger force when it collides with a stationary object (Maloney, 1984).

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Misconceptions are one source of learners’ struggles when trying to understand Newton’s Third Law (Bao et al., 2002).

Challenges of accurate mental models. Craik (1943) first used the term mental

models. Later, Gentner and Stevens (1983) used the term to describe beliefs developed through observing the real world, a prior knowledge used to form understanding of the world. Cognitive scientists have studied mental models, and many cognitive scientists are utilizing prior knowledge and perceptions to explain new situations. One or many misconceptions can be included in a mental model, or misconceptions can be included along with many truths to combine to form a mental model (Davidson, Dove, & Weltz, 1999).

Some commonly held beliefs are that only living objects can exert forces, nonliving objects impede or stop motion, and a greater force is needed for objects to move than for objects to remain stationary. The use of force in everyday language and nomenclature such as: “the force be with you”; “police force”; or the “force of the conversation” leads learners to develop misunderstandings of force as it is used in physics (Halloun & Hestenes, 1985a). Maloney (1984) found learners’ beliefs to be inconsistent with Newton’s Third Law. Other researchers have concluded that preexisting beliefs have a detrimental effect on the learners’ performance in physics (Halloun & Hestenes, 1987).

Smith and Wittman (2007) analyzed scenarios in which objects were pushed and in which objects collided (see Table 2.2). In the first scenario, pushing involved the interaction of two objects for an extended period of time. During the pushing, objects of

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differing masses remained at a constant speed, sped up, or slowed down. Many learners thought that the object with the larger mass had the larger force. Some learners thought that the first object exerted force and the second object only felt force. If the larger mass was moving and the smaller mass was stationary, learners thought that the force was largely due to motion. Many learners believed that the forces were equal if the objects moved at constant speeds. In the collision scenario, learners observed collisions between cars and trucks, which led to the misconception that the larger truck had a greater force because the smaller car received the most damage (Smith & Wittman, 2007).

Learners can apply correct conceptual understanding in a particular situation, while in different scenarios learners often revert back to old misconceptions. Learners’ previous educational instruction, everyday experiences, and thoughts influence their conceptual understanding of physics instruction (Bao & Redish, 2006). Minstrell (2008) coded the following facets held by learners:

 Stronger exerts more force.

 One with more motion exerts more force.  More active/energetic exerts more force.  Bigger/heavier exerts more force.

Another example of a misconception is when learners believe the reason a horse can pull a cart is because the horse pulls harder on the cart than the cart pulls on the horse (Olenick, 2000). In one study, Maloney found that learners believe in the

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object has a greater mass (Maloney, 1984). Learners believed that the object with the larger mass, the greater velocity, or the object doing the pushing, is the dominating object with the greater force (Bao et al., 2002; Maloney, 1984).

Table 2.2

Words and Phrases Associated with Learners’ Common Misconceptions Pertaining to Newton’s Third Law

Words and phrases Misconceptions

Objects being pushed Larger mass objects exert greater force

Objects being pushed Pushing objects exert force, objects being pushed

only feel the force

Objects moving Moving objects have more force

Objects move at constant velocity Forces are equal

Objects colliding Larger mass objects exert greater force

Objects colliding Smaller object displays more damage, therefore

less force

Learning Newton’s Third Law and its many facets poses a difficult problem for learners because of their preconceived ideas, which can also affect instruction

(Bao et al., 2002). These authors further explain that mental models are constructed by learners in association with specific topics during instruction. Often common

misconceptions are integrated by learners into their mental models. These mental

models are constructed by learners throughout daily lessons, teacher-directed instruction, and laboratory activities. Learners refer to their mental models during problem solving and consistently retreat to their misconceptions when answering questions about new

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material. Sometimes, however, they may use diverse mental models on different questions.

In a study by Bao et al. (2002), questions were developed to assess only one feature of a concept at a time. The authors found that seven out of nine undergraduate learners at Kansas State University consistently applied one dominant misconception dealing with Newton’s laws when answering questions concerning force. The rest of the learners applied a mixed or confused state, containing some correct and some incorrect mental models. They also found that some learners applied conceptual understanding one way with one question and when asked a different question, used a different conceptual misunderstanding. Bao & Redish (2006) reported five years later that learners’ applications of mental models concerning Newton’s Third Law varied with the situation.

Other researchers have investigated learners’ thinking about Newton’s laws. Traditional teaching methods do not always change a learner’s understanding of Newton’s laws. Thornton and Sokoloff (1998) tested learners’ knowledge regarding Newton’s laws before and after instruction. They concluded that learners’

understandings of the laws were not changed through traditional teaching methods. Their study demonstrated that conceptual understanding was gained through active application and hands-on laboratory activities.

One of the most important things a teacher can do is find out what a learner already knows (Ausubel, 1960; Novak & Gowin, 1984; NRC, 2000a). Previous knowledge will alter how learners add new knowledge to already held common-sense

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beliefs (NRC, 2000a). Certain common beliefs should be considered when teaching Newtonian physics. Learners develop their beliefs through experiencing the world over years. As mentioned, some publications label these beliefs as misconceptions (Halloun & Hestenes, 1985a; Halloun & Hestenes, 1985b). Minstrell (2008) labels such beliefs as facets (http://depts.washington.edu/huntlab/diagnoser/facetcode. html#400). Many of the learners’ common misconceptions or misbeliefs are labeled by some as Aristotelian due to the fact that Aristotle held some of these same ideas himself (Halloun &

Hestenes, 1985a).

Learners need opportunities to assess and revise their conceptual understanding (Barron, 1998). With computer simulations, learners can change the amount of force and the direction of the force, which provides visual feedback. Learners are able to self-assess as they work through answering questions (Dancy et al., 2002). Utilizing computer simulations allows learners to test their answers and adjust their conceptual understanding (Christian & Belloni, 2004). Application of what they have learned offers learners a chance to demonstrate their conceptual understanding (Barron, 1998).

Animations contain embedded scaffolding. Learners can alter their mental models as new observations are made (Leonard et al., 1996). Published research states that conceptual understanding does increase with the use of Physlet® simulations in physics (Dancy et al., 2002). Physlets® are computer simulations developed by Davidson College to assist students in developing conceptual understanding. Wolfgang Christian and Mario Belloni construct computer simulations for their physics courses named Physlets. The students interact with the computer simulations to reinforce a lecture,

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small group inquiry activities, visualization of mathematical homework problems or hands-on laboratory investigations. The word Physlets® was derived from physics applets. University of Colorado has developed computer simulations which they call PhETs which stands for physics education technology. PhETs are created and tested for accurate visual presentation of a physics concept in computer simulation form (Adams, et al., 2008; Finkelstein et al., 2006; McKagan et al., 2009; McKagan et al., 2008; Perkins, et al., 2006).

Learners learn through active participation (Driver, 1989). By being actively involved with multiple representations, learners are better able to take abstract concepts and formulate concrete ideas regarding Newton’s three laws. Research has shown an increase in retention of concepts when learners use multiple representations such as computer animations, computer simulations, and virtual laboratories (NRC, 2000b). Information presented in these multiple formats is readily transferred to other situations, including assessments (Jacobson & Kozma, 2000; Monaghan & Clement, 1999).

Challenges with English language learners. One problem faced when

attempting to teach learners in a native language other than English is the number of native languages learners bring to a classroom. In California, more than 90 different languages are spoken (Becker, 1993). As many as ten different languages can exist in one school. Teachers and school districts are overwhelmed by trying to meet the many different language needs of their learners. Arizona categorizes native languages, such as American Indians dialects, as languages originating outside the United States (Barclay, 1983).

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ESL programs place learners in regular content classrooms with instruction in English. Extra instruction is presented utilizing curriculum designed to teach non-native English speakers. The learner’s native language does not need to be available in using an English as a second language approach (Baker & de Kanter, 1983). Learners with limited English language skills are often placed in science classrooms where English is the language of instruction. Academic difficulties are encountered by these learners.